Beam collimated light emitting module with light color mixed chamber

ABSTRACT

A beam collimated light emitting module with a light color mixed chamber includes a light holder, a light source assembly located on the light holder, an optical lens covering the light source assembly, and a reflector. The optical lens includes a first light exit surface, a light entrance surface, and a second light exit surface. The first light exit surface has a round-shaped concave surface formed by recessing the first light exit surface, and the aspheric curvature of the concave surface is gradually decreased in an outward direction away from the center of the optical lens. The reflector surrounds the optical lens. When the light source assembly emits light, the bluish white light and the yellowish white light of the light source assembly are refracted by the concave surface, and next the bluish white light and the yellowish white light are reflected by the reflector.

RELATED APPLICATIONS

This application claims priority to Taiwanese Application Serial Number103102321, filed Jan. 22, 2014, which is herein incorporated byreference.

BACKGROUND

1. Field of Invention

The present invention relates to a light emitting module. Moreparticularly, the present invention relates to a beam collimated lightemitting module with a light color mixed chamber.

2. Description of Related Art

Lighting devices are indispensable tools in our daily lives.Conventional lighting devices usually use light bulbs or lamps as thelight sources. Fluorescent tubes, incandescent bulbs, and halogen lightbulbs are most frequently used among these light bulbs or lamps but arenot energy economic. Therefore, lighting devices includinglight-emitting diodes (LED) as light sources have become more and morepopular in recent years. Compared with the incandescent bulbs, LED lightsources have the advantages such as long lifespan, low energyconsumption, good shock resistance, and high brightness. Moreover, LEDlight source may be manufactured by a blue light emitting chip coveredby yellow phosphor powders. When the blue light emitting chip emitslight, a blue light enters and excites the yellow phosphor powders, suchthat the center area of the LED light source with high-density chips isapt to emit a bluish white light, and the surrounding area of the LEDlight source with low-density chips tend to emit a yellowish whitelight. Such phenomenon is more obviously observed in the type ofintegrated packaging LEDs.

A conventional lighting device utilizing a LED as a light source, e.g.,a flashlight, a streetlight, or a car lamp, may be composed of a lightholder and a light source, and may optionally include a reflector or alens. If the lighting device is composed of the light holder, the lightsource, and the reflector, although the light of the light source can bereflected by the reflector to improve the beam collimation of thelighting device, the phenomenon for the center area of the LED lightsource emitting the bluish white light and the surrounding area of theLED light source emitting the yellowish white light still exists andreduces the uniformity of the light color. Furthermore, If the lightingdevice is composed of the light holder, the light source, and the lens,although the micro structure of the lens can be used to scatter thecentral bluish white light and the surrounding yellowish white light toimprove the uniformity of the light color, the light of the lightingdevice is therefore diverged due to the scattering of the light. As aresult, the beam collimation of the lighting device may be degraded.

It is difficult to simultaneously improve the uniformity of the lightcolor and the beam collimation for the conventional lighting device. Assuch, the optical performance of the lighting device is limited and theconsumers' requirement is unsatisfied.

SUMMARY

An aspect of the present invention is to provide a beam collimated lightemitting module with a light color mixed chamber.

According to an embodiment of the present invention, a beam collimatedlight emitting module with a light color mixed chamber includes a lightholder, a light source assembly, an optical lens, and a reflector. Thelight source assembly is located on the light holder. The optical lenscovers the light source assembly. The optical lens includes a firstlight exit surface, a light entrance surface, and a second light exitsurface. A round-shaped concave surface is formed by recessing the firstlight exit surface. An aspheric curvature of the concave surface isgradually decreased in an outward direction away from the center of theoptical lens. A round-shaped accommodating space is formed by recessingthe light entrance surface for accommodating the light source assembly.The second light exit surface is a side surface located between thefirst light exit surface and the light entrance surface. An end of theside surface is connected to the first light exit surface, and anotherend of the side surface is connected to the light entrance surface. Thereflector surrounds the optical lens. The reflector is a hollowstructure having a first opening and a second opening. The caliber ofthe first opening is greater than the caliber of the second opening. Theoptical lens passes through the second opening of the reflector. Whenthe light source assembly emits light, the light source assembly emits afirst color light and a second color light surrounding the first colorlight, the first and second color lights are refracted by the concavesurface, such that the first and second color lights are mixed at afirst time. Thereafter, the second color light refracted by the concavesurface is reflected by the reflector, such that the second color lightreflected by the reflector and the first color light refracted by theconcave surface are mixed at a second time or plural times.

In one embodiment of the present invention, the concave surface has afirst curved surface with a first aspheric curvature and a second curvedsurface with a second aspheric curvature. An end of the first curvedsurface is connected to an end of the second curved surface. The firstand second aspheric curvatures are gradually decreased in an outwarddirection away from the center of the optical lens.

In one embodiment of the present invention, the light source assembly isa light emitting diode or an organic light emitting diode.

In one embodiment of the present invention, the first color light is abluish white light, and the second color light is a yellowish whitelight.

In one embodiment of the present invention, a first time light-mixedposition of the first and second color lights is in the optical lens.

In one embodiment of the present invention, a second time light-mixedposition of the first and second color lights is between the opticallens and the reflector.

In one embodiment of the present invention, the aspheric curvature ofthe concave surface refracting the first color light is greater than theaspheric curvature of the concave surface refracting the second colorlight.

In one embodiment of the present invention, the concave surface of theoptical lens has an end point located at the axis of the optical lensand facing the light source assembly. A gap is between the end point andthe light source assembly.

In one embodiment of the present invention, the light entrance surfaceis recessed toward the first light exit surface, and the first lightexit surface is recessed toward the light entrance surface.

In one embodiment of the present invention, the first color lightrefracted by the concave surface is reflected by a first reflectingposition of the reflector. The second color light refracted by theconcave surface is reflected by a second reflecting position of thereflector. A distance between the first reflecting position and the axisof the optical lens is greater than a distance between the secondreflecting position and the axis of the optical lens.

In the aforementioned embodiments of the present invention, since theconcave surface has the aspheric curvature that is gradually decreasedin the outward direction away from the center of the optical lens, whenthe light source assembly emits light, the first color light (e.g., abluish white light) and the second color light (e.g., a yellowish whitelight) emitted by the light source assembly may be refracted to thereflector by the concave surface, such that the first and second colorlights may be mixed at the first time. Thereafter, the second colorlight refracted by the concave surface may be reflected by thereflector, such that the second color light reflected by the reflectorand the first color light refracted by the concave surface are mixed atthe second time. That is to say, the light emitting module of thepresent invention utilizes the collocation design of the optical lensand the reflector to mix the first and second color lights at pluraltimes in the light emitting module, and next the first and second colorlights are reflected to divert by the reflector to emit in the samedirection. Therefore, the beam collimated light emitting module with thelight color mixed chamber of the present invention can improve theuniformity of the light color and the beam collimation simultaneously.

It is to be understood that both the foregoing general description andthe following detailed description are by examples, and are intended toprovide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the followingdetailed description of the embodiments, with reference made to theaccompanying drawings as follows:

FIG. 1 is a perspective view of a beam collimated light emitting modulewith a light color mixed chamber according to an embodiment of thepresent invention;

FIG. 2 is a cross-sectional view of the light emitting module takenalong line 2-2 shown in FIG. 1; and

FIG. 3 is a partial enlarged view of the light emitting module shown inFIG. 2.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or like parts.

In the following description, “beam collimation” may be referred to asthe concentration level of the light emitted by the light emittingmodule. That is to say, “beam collimation” is the capability ofgenerating the light emitted in the same direction.

Moreover, “uniformity of the light color” means that the light colormixed level of the first color light (e.g., a bluish white light)adjacent to the center area and the second color light (e.g., ayellowish white light) adjacent to the surrounding area that are emittedby the LED light source assembly in the light emitting module when thelight emitting module emits light.

FIG. 1 is a perspective view of a beam collimated light emitting module100 with a light color mixed chamber according to an embodiment of thepresent invention. FIG. 2 is a cross-sectional view of the lightemitting module 100 taken along line 2-2 shown in FIG. 1. As shown inFIG. 1 and FIG. 2, the light emitting module 100 includes a light holder110, a light source assembly 120, an optical lens 130, and a reflector140. The light source assembly 120 is located on the light holder 110.The optical lens 130 covers the light source assembly 120. The opticallens 130 includes a first light exit surface 134, a light entrancesurface 136, and a second light exit surface 138. A round-shaped concavesurface 132 is formed by recessing the first light exit surface 134, andthe aspheric curvature of the concave surface 132 is gradually decreasedin an outward direction away from the center of the optical lens 130.The concave surface 132 may be referred to as a total internalreflection (TIR) surface. The concave surface 132 may include pluralconcave surfaces with aspheric curvatures, and the number of the concavesurfaces does not limit the present invention. For example, in thisembodiment, the concave surface 132 has a first curved surface 131 witha first aspheric curvature and a second curved surface 133 with a secondaspheric curvature, and an end of the first curved surface 131 isconnected to an end of the second curved surface 133. The first andsecond aspheric curvatures are gradually decreased in an outwarddirection away from the center of the optical lens 130.

A round-shaped accommodating space 137 is formed by recessing the lightentrance surface 136 for accommodating the light source assembly 120.The second light exit surface 138 is a side surface located between thefirst light exit surface 134 and the light entrance surface 136. An endof the side surface 138 is connected to the first light exit surface134, and another end of the side surface 138 is connected to the lightentrance surface 136. Moreover, the light entrance surface 136 isrecessed toward the first light exit surface 134, and the first lightexit surface 134 is recessed toward the light entrance surface 136.

The optical lens 130 may be made of a material that includes glass orplastic, but the present invention is not limited in this regard. Thereflector 140 surrounds the optical lens 130. The reflector 140 is ahollow structure having a first opening 142 and a second opening 144.The caliber of the first opening 142 is greater than the caliber of thesecond opening 144. The optical lens 130 passes through the secondopening 144 of the reflector 140.

The light source assembly 120 may be a light emitting diode (LED) or anorganic light emitting diode. The light source assembly 120 may beelectrically connected to an external power to provide current for chips124. When the light source assembly 120 emits light, the light emittedby the light source assembly 120 can be refracted by the optical lens130 and reflected by the reflector 140. Furthermore, the light holder110 may has plural heat dissipation fins 112. The light holder 110 maybe made of a material that includes metal, such as copper, aluminum, oriron. When the light source assembly 120 emits light, the light holder110 may transfer heat to the heat dissipation fins 112 to reduce thetemperature of the light source assembly 120.

In this embodiment, the light source assembly 120 includes blue lightingchips 124, packaging glue 126 with yellow phosphor powders, and asubstrate 122. The packaging glue 126 may be made of a material thatincludes epoxy resin. The packaging glue 126 with yellow phosphorpowders covers the blue lighting chips 124. Therefore, when the bluelighting chips 124 emit light, the light adjacent to the center area ofthe light source assembly 120 excited by the blue lighting chips 124 andthe packaging glue 126 is a bluish white light, and the light adjacentto the surrounding area of the light source assembly 120 is a yellowishwhite light due to the weaker blue light. As a result, the light sourceassembly 120 may emit a first color light L1 and a second color light L2surrounding the first color light L1. The first color light L1 is thebluish white light emitted by the center area of the light sourceassembly 120, and the second color light L2 is the yellowish white lightemitted by the surrounding area of the light source assembly 120.However, in another embodiment, the combination of the lighting chips124 and the packaging glue 126 is not limited in the present invention.For example, the light source assembly 120 may utilize ultraviolet (UV)lighting chips 124 and packaging glue 126 with red, green, and bluephosphor powders, and the present invention is not limited in thisregard. In addition, lighting chips 124 may selectively use red, green,and blue chips with single color as deemed necessary by designers.

It is to be noted that the first and second color lights L1, L2 onlymean that the color variation from the center area of the light sourceassembly 120 to the surrounding area of the light source assembly 120may be substantially recognized the bluish white light and the yellowishwhite light. Practically, the color variation in an outward directionaway from the center of the light source assembly 120 is graduallychanged.

It is to be noted that the connection relationships and the materials ofthe elements described above will not be repeated in the followingdescription. In the following description, the light emitted by thelighting chip 124 that is aligned with the axis L of the optical lens130 will be described as an example.

After the light source assembly 120 emits the first and second colorlights L1, L2, the concave surface 132 of the optical lens 130 refractsthe first color light L1 (e.g., a bluish white light) and the secondcolor light L2 (e.g., a yellowish white light) to a first timelight-mixed position R1 by the design of the concave surface 132, suchthat the first and second color lights L1, L2 are mixed at the firsttime. After the first and second color lights L1, L2 are mixed at thefirst time, the first and second color lights L1, L2 are close to whitelights. In this embodiment, the first time light-mixed position R1 ofthe first and second color lights L1, L2 is in the optical lens 130.Thereafter, the second color light L2 refracted by the concave surface132 may be reflected to divert in the same direction by the reflector140, and the first color light L1 may be refracted to a second timelight-mixed position R2 by the design of the aspheric curvature of theconcave surface 132, such that the second color light L2 reflected bythe reflector 140 and the first color light L1 refracted by the concavesurface 132 are mixed at the second time. After the first and secondcolor lights L1, L2 are mixed at the second time, the first and secondcolor lights L1, L2 can be assured to be more close to white lights.However, the light-mixed time of the first and second color lights L1,L2 is not limited to two times, and the present invention is not limitedin this regard.

In this embodiment, the second time light-mixed position R2 of the firstand second color lights L1, L2 is between the optical lens 130 and thereflector 140. The area surrounded by the reflector 140 may be regardedas the light color mixed chamber of the light emitting module 100.

FIG. 3 is a partial enlarged view of the light emitting module 100 shownin FIG. 2. As shown in FIG. 2 and FIG. 3, since the first asphericcurvature of the first cured surface 131 of the concave surface 132 andthe second aspheric curvature of the second cured surface 133 of theconcave surface 132 are gradually decreased in an outward direction awayfrom the center of the optical lens 130, and the second color light L2surrounds the first color light L1, the aspheric curvature of theconcave surface 132 refracting the first color light L1 is greater thanthe aspheric curvature of the concave surface 132 refracting the secondcolor light L2. After the first color light L1 is refracted by theconcave surface 132, the first color light L1 can be reflected by thefirst reflecting position R3 of the reflector 140. After the secondcolor light L2 is refracted by the concave surface 132, the second colorlight L2 can be reflected by the second reflecting position R4 of thereflector 140. A distance between the first reflecting position R3 andthe axis L of the optical lens 130 is greater than a distance betweenthe second reflecting position R4 and the axis L of the optical lens130. That is to say, the second reflecting position R4 of the opticallens 130 is more close to the optical lens 130 than the first reflectingposition R3.

After the first and second color lights L1, L2 are both reflected by thereflector 140, the first and second color lights L1, L2 may divert toemit in the same direction D. Therefore, the beam collimation of thelight emitting module 100 may be improved. The first and second colorlights L1, L2 have been mixed at the first time in the optical lens 130,and the first and second color lights L1, L2 are further mixed at thesecond time between the optical lens 130 and the reflector 140.Therefore, when the first and second color lights L1, L2 emit in thesame direction D, the first and second color lights L1, L2 have beenmixed to uniform white lights, such that the uniformity of the lightcolor of the light emitting module 100 may be improved. The beamcollimated light emitting module 100 with the light color mixed chamberof the present invention utilizes the collocation design of the opticallens 130 and the reflector 140 to mix the first and second color lightsL1, L2 at plural times in the light emitting module 100, and next thefirst and second color lights L1, L2 are reflected to divert by thereflector 140 to emit in the same direction D. Therefore, the lightemitting module 100 can improve the uniformity of the light color andthe beam collimation simultaneously.

Furthermore, the concave surface 132 of the optical lens 130 has an endpoint P. The end point P is located at the axis L of the optical lens130 and faces the light source assembly 120, and a gap H is between theend point P and the light source assembly 120. As a result, the lightemitting position of the light source assembly 120 can be lifted up tothe end point P, such that the beam collimation of the light emittingmodule 100 may be further improved, and the volume of the whole lightemitting module 100 may be reduced to save the space and the cost. Forexample, the volume of the reflector 140 may be reduced.

In addition, since the light emitting module 100 of an optical systemcan divert the light at the concave surface 132 of the first light exitsurface 134 by the capability of the central optical lens 130, the lightemitting surface of the light source assembly 120 adjacent to the bottomof the optical lens 130 is similarly lifted up in virtual to the firstlight exit surface 134 and emit light to the reflector 140. The designheight of the first light exit surface 134 is equal to the height of thefocus of the reflector 140, such that the light may be easilycollimated, and the design size of the optical system may besignificantly reduced. The aforesaid focus of the reflector 140 meansthat when a light source is located at a certain position in thereflector 140, the reflector 140 can divert all lights of the lightsource to emit outward in the same direction, and the position may bereferred to as the focus of the reflector 140. The light emitting module100 utilizes the combination of the light source assembly 120 and theoptical lens 130 to lift up the light of the light source assembly 120to the first light exit surface 134 of the optical lens 130 to emitlight. That is to say, the light source is lifted up to the position ofthe focus of the reflector 140, such that the light may be preventedfrom being scattered and losing the energy of the light source.

Compared with the beam collimated light emitting module with the lightcolor mixed chamber and a conventional lighting device, since theaspheric curvature of the concave surface is gradually decreased in theoutward direction away from the center of the optical lens, when thelight source assembly emits light, the first color light (e.g., a bluishwhite light) and the second color light (e.g., a yellowish white light)emitted by the light source assembly may be refracted to the reflectorby the concave surface, such that the first and second color lights may_(be) mixed at the first time. Thereafter, the second color lightrefracted by the concave surface may be reflected by the reflector, suchthat the second color light reflected by the reflector and the firstcolor light refracted by the concave surface are mixed at the secondtime. That is to say, the light emitting module of the present inventionutilizes the collocation design of the optical lens and the reflector tomix the first and second color lights at plural times in the lightemitting module, and next the first and second color lights arereflected to divert by the reflector to emit in the same direction.Therefore, the uniformity of the light color and the beam collimation ofthe light emitting module may be improved simultaneously.

Although the present invention has been described in considerable detailwith reference to certain embodiments thereof, other embodiments arepossible. Therefore, the spirit and scope of the appended claims shouldnot be limited to the description of the embodiments contained herein.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims.

What is claimed is:
 1. A beam collimated light emitting module with a light color mixed chamber, comprising: a light holder; a light source assembly located on the light holder; and an optical lens covering the light source assembly, comprising: a first light exit surface, wherein a round-shaped concave surface is formed by recessing the first light exit surface, and an aspheric curvature of the concave surface is gradually decreased in an outward direction away from a center of the optical lens; a light entrance surface, wherein a round-shaped accommodating space is formed by recessing the light entrance surface for accommodating the light source assembly; and a second light exit surface, wherein the second light exit surface is a side surface located between the first light exit surface and the light entrance surface, an end of the side surface is connected to the first light exit surface, and another end of the side surface is connected to the light entrance surface; and a reflector surrounding the optical lens, wherein the reflector is a hollow structure having a first opening and a second opening, a caliber of the first opening is greater than a caliber of the second opening, and the optical lens passes through the second opening of the reflector, wherein when the light source assembly emits light, the light source assembly emits a first color light and a second color light surrounding the first color light, the first and second color lights are refracted by the concave surface, such that the first and second color lights are mixed at a first time; and the second color light refracted by the concave surface is reflected by the reflector, such that the second color light reflected by the reflector and the first color light refracted by the concave surface are mixed at a second time.
 2. The emitting module of claim 1, wherein the concave surface has a first curved surface with a first aspheric curvature and a second curved surface with a second aspheric curvature, an end of the first curved surface is connected to an end of the second curved surface, and the first and second aspheric curvatures are gradually decreased in an outward direction away from the center of the optical lens.
 3. The emitting module of claim 1, wherein the light source assembly is a light emitting diode or an organic light emitting diode.
 4. The emitting module of claim 3, wherein the first color light is a bluish white light, and the second color light is a yellowish white light.
 5. The emitting module of claim 1, wherein a first time light-mixed position of the first and second color lights is in the optical lens.
 6. The emitting module of claim 5, wherein a second time light-mixed position of the first and second color lights is between the optical lens and the reflector.
 7. The emitting module of claim 1, wherein the aspheric curvature of the concave surface refracting the first color light is greater than the aspheric curvature of the concave surface refracting the second color light.
 8. The emitting module of claim 1, wherein the concave surface of the optical lens has an end point located at an axis of the optical lens and facing the light source assembly, and a gap is between the end point and the light source assembly.
 9. The emitting module of claim 1, wherein the light entrance surface is recessed toward the first light exit surface, and the first light exit surface is recessed toward the light entrance surface.
 10. The emitting module of claim 1, wherein the first color light refracted by the concave surface is reflected by a first reflecting position of the reflector, the second color light refracted by the concave surface is reflected by a second reflecting position of the reflector, and a distance between the first reflecting position and an axis of the optical lens is greater than a distance between the second reflecting position and an axis of the optical lens. 